40 research outputs found

    Exact-Exchange Kohn-Sham formalism applied to one-dimensional periodic electronic systems

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    The Exact-Exchange (EXX) Kohn-Sham formalism, which treats exchange interactions exactly within density-functional theory, is applied to one-dimensional periodic systems. The underlying implementation does not rely on specific symmetries of the considered system and can be applied to any kind of periodic structure in one to three dimensions. As a test system, transtrans-polyacetylene, both in form of an isolated chain and in the bulk geometry has been investigated. Within the EXX scheme, bandstructures and independent particle response functions are calculated and compared to experimental data as well as to data calculated by several other methods. Compared to results from the local-density approximation, the EXX method leads to an increased value for the band gap, in line with similar observations for three-dimensional semiconductors. An inclusion of correlation potentials within the local density approximation or generalized gradient approximations leads to only negligible effects in the bandstructure. The EXX band gaps are in good agreement with experimental data for bulk transtrans-polyacetylene. Packing effects of the chains in bulk transtrans-polyacetylene are found to lower the band gap by about 0.5 eV

    Armodafinil versus Modafinil in Patients of Excessive Sleepiness Associated with Shift Work Sleep Disorder: A Randomized Double Blind Multicentric Clinical Trial

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    Aim. To compare the efficacy and safety of armodafinil, the R-enantiomer of modafinil, with modafinil in patients of shift work sleep disorder (SWSD). Material and Methods. This was a 12-week, randomized, comparative, double-blind, multicentric, parallel-group study in 211 patients of SWSD, receiving armodafinil (150 mg) or modafinil (200 mg) one hour prior to the night shift. Outcome Measures. Efficacy was assessed by change in stanford sleepiness score (SSS) by at least 2 grades (responder) and global assessment for efficacy. Safety was assessed by incidence of adverse events, change in laboratory parameters, ECG, and global assessment of tolerability. Results. Both modafinil and armodafinil significantly improved sleepiness mean grades as compared to baseline (P < .0001). Responder rates with armodafinil (72.12%) and modafinil (74.29%) were comparable (P = .76). Adverse event incidences were comparable. Conclusion. Armodafinil was found to be safe and effective in the treatment of SWSD in Indian patients. The study did not demonstrate any difference in efficacy and safety of armodafinil 150 mg and modafinil 200 mg

    Drug-prescribing patterns during pregnancy in the tertiary care hospitals of Pakistan: a cross sectional study

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    <p>Abstract</p> <p>Background</p> <p>The rationale for use of drugs during pregnancy requires a careful assessment as in addition to the mother, the health and life of her unborn child is also at stake. Information on the use of drugs during pregnancy is not available in Pakistan. The aim of this study was to evaluate the patterns of drug prescriptions to pregnant women in tertiary care hospitals of Pakistan.</p> <p>Methods</p> <p>This was a cross-sectional study conducted at five tertiary care hospitals of Pakistan. Copies of outpatient medicinal prescriptions given to pregnant patients attending the antenatal clinics were collected. The drugs were classified according to the pharmacological class and their teratogenic potential.</p> <p>Results</p> <p>All the pregnant women attending the antenatal clinics received a prescription containing at least one drug. A total of 3769 distinct prescriptions given to different women were collected. Majority of the women who received the prescriptions belonged to third trimester (55.4%) followed by second (33.6%) and first trimester (11.0%). On an average, each prescription contained 1.66 ± 0.14 drugs. The obstetricians at Civil Hospital, Karachi and Chandka Medical College Hospital, Larkana showed a tendency of prescribing lesser number of drugs compared to those in other hospitals. Anti-anemic drugs including iron preparations and vitamin and mineral supplements (79.4%) were the most frequently prescribed drugs followed by analgesics (6.2%) and anti-bacterials (2.2%). 739 women (19.6%) received prescriptions containing drugs other than vitamin or mineral supplements. Only 1275 (21.6%) of all the prescribed drugs (n = 6100) were outside this vitamin/mineral supplement class. Out of these 1275 drugs, 29 (2.3%) drugs were prescribed which are considered to be teratogenic. Misoprostol was the most frequently prescribed (n = 6) among the teratogenic drugs followed by carbimazole (n = 5) and methotrexate (n = 5). Twenty nine pregnant women (0.8% of all the women studied) were prescribed these teratogenic drugs.</p> <p>Conclusion</p> <p>Less than one percent of the pregnant women attending tertiary care hospitals in Pakistan are prescribed teratogenic drugs. The prescribing practices of Pakistani physicians are similar to those in western countries.</p

    Effects of increased paternal age on sperm quality, reproductive outcome and associated epigenetic risks to offspring

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    Recent advances in charge trap flash memories

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    This paper reviews recent advances in Charge Trap Flash (CTF) memories. CTFs are predicted to replace the traditional floating-gate flash devices beyond the 32 nm node. The paper focuses on work done at IIT Bombay in the areas of both nitride-based SONOS devices as well as nanocrystal (NC)-based devices. For SONOS devices, results are presented for optimization of the nitride layer to obtain the best characteristics, and the simulation of the program/erase transients. For NC devices, experimental characteristics of single and dual layer cells, as well as simulation results are presented

    Participatory development of a framework to actively involve people living with dementia and those from their social network, and healthcare professionals in conducting a systematic review: the DECIDE-SR protocol

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    Abstract Background Systematic reviews summarize and evaluate relevant studies to contribute to evidence-based practice. Internationally, researchers have reached a consensus that the active involvement of the public leads to better research. Despite this agreement, there are many reviews of research concerning healthcare interventions intended to promote the care of people living with dementia and those from their social network (e.g., close contacts, both family and non-family members) primarily involve only healthcare professionals and other experts. Due to the lack of a dementia-sensitive framework to actively involve people living with dementia and those from their social network, and healthcare professionals as co-researchers in systematic reviews, it is important to develop a framework to inform practice. Methods For this framework development process, we will recruit four people living with dementia and a total of four people from their social network, and three healthcare professionals working in acute or long-term care settings. We will conduct regular meetings with these groups of the public and healthcare professionals to include them in all stages of the systematic review. We will also identify and develop methods necessary to ensure meaningful involvement. The results will be documented and analyzed for the development of a framework. For the planning and preparation for these meetings, as well as the conduct of the meetings themselves, we will be guided by the principles of the INVOLVE approach. In addition, the ACTIVE framework will be used to guide the degree of involvement and the stage in the review process. Discussion We assume that our transparent approach to the development of a framework to support the active involvement of people living with dementia and those from their social network, and healthcare professionals in systematic reviews will serve as an impetus for and provide guidance to other researchers with the goal of increasing researchers’ focus on this topic and facilitating systematic reviews that apply participatory approaches. Trial registration: Trial registration is unnecessary as no intervention study will be conducted
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